The edition · Anaesthesiology
A normal MAP with a narrow pulse pressure is not a safe pressure
In 30,039 non-cardiac cases, a narrow pulse pressure raised the odds of postoperative AKI even when the MAP stayed above 65 — and the stroke volume index behind it was 27 against 47. Plus COX-2 inhibitors measured on function rather than a pain score, an autonomic phenotype you can pull from the record, and dexmedetomidine given the night before.
The edition in brief
Today's anaesthesiology edition opens with a retrospective cohort of 30,039 adult non-cardiac surgical patients in South Korea. Stratified by median intraoperative pulse pressure, narrow pulse pressure (under 40 mmHg) was independently associated with postoperative acute kidney injury (odds ratio 1.66, 95% CI 1.42-1.94). Hypotension with a normal pulse pressure was not (OR 1.09, 0.86-1.38), while normotension with a narrow pulse pressure was (OR 1.56, 1.27-1.89). Both together gave the highest risk (OR 1.85, 1.21-2.81). Stroke volume index in the normotensive narrow-pulse-pressure group was 27 ml/m² against 47 in the hypotensive reference group, and risk became significant after 40 minutes of exposure. A systematic review of 38 randomised trials and 5,424 adults assessed perioperative selective COX-2 inhibitors using multidimensional instruments — pain interference with daily function rather than a pain score. Brief Pain Inventory mean difference was -1.1 (95% CI -1.4 to -0.8, moderate certainty), against a minimal important difference of 1.0. Chronic pain incidence fell (OR 0.44, 0.21-0.93, low certainty) and quality of recovery improved, with no difference in renal, gastrointestinal, bone healing, cardiac or mortality outcomes. In 612 propensity-matched pairs aged 65 and over, an autonomic vulnerability phenotype built from routine record data was associated with myocardial injury after non-cardiac surgery (14.2% versus 8.7%), with the excess concentrated in the highest hypotension quartile. And intranasal dexmedetomidine the night before arthroplasty was non-inferior to a pre-induction infusion for delirium.
The MAP was fine. The flow was not.
Treat a narrowing pulse pressure as a perfusion warning even when the MAP is on target, and ask whether you are treating flow or only pressure.
COX-2 inhibitors measured on what the patient can do, not on a number they report
Keep selective COX-2 inhibitors in the multimodal regimen — the benefit shows up in function, and the feared harms did not appear.
An autonomic phenotype you can build from the notes, before the patient arrives
Flag the diabetic or hypertensive patient over 65 with neuropathy or orthostatic symptoms, and hold their pressure tighter than you would otherwise.
Look at the pulse pressure before you turn the vasopressor up
Check the pulse pressure before escalating a vasopressor — it tells you whether you are treating tone or treating flow.
Dexmedetomidine the night before did as well as an infusion on the day
Consider intranasal dexmedetomidine on the ward the night before elderly arthroplasty instead of a pre-induction infusion.
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